diff options
| author | Christian König | 2020-09-14 15:09:33 +0200 |
|---|---|---|
| committer | Christian König | 2020-11-05 13:03:52 +0100 |
| commit | 2b5b95b1ff3d70a95013a45e3b5b90f1daf42348 (patch) | |
| tree | 0d0d804862b63c20500e6e947931d18f440dbb45 /mm/mmap.c | |
| parent | 0227da01f2559626396af5f6c7453360db86c1f6 (diff) | |
mm: introduce vma_set_file function v4
Add the new vma_set_file() function to allow changing
vma->vm_file with the necessary refcount dance.
v2: add more users of this.
v3: add missing EXPORT_SYMBOL, rebase on mmap cleanup,
add comments why we drop the reference on two occasions.
v4: make it clear that changing an anonymous vma is illegal.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v2)
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/394773/
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 30a4e8412a58..b0093cc69240 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -137,6 +137,18 @@ void vma_set_page_prot(struct vm_area_struct *vma) } /* + * Change backing file, only valid to use during initial VMA setup. + */ +void vma_set_file(struct vm_area_struct *vma, struct file *file) +{ + /* Changing an anonymous vma with this is illegal */ + get_file(file); + swap(vma->vm_file, file); + fput(file); +} +EXPORT_SYMBOL(vma_set_file); + +/* * Requires inode->i_mapping->i_mmap_rwsem */ static void __remove_shared_vm_struct(struct vm_area_struct *vma, |